Getting Frustrated

[Subliminal]

So, I've had several issues that have plagued me for...well, as long as I can remember. A while now, at any rate.

First, I don't feel that the engine runs as smooth as it should. Sounds/feels like it's got a cam or something...Hard to explain, but maybe like a miss, or the flywheel is out of balance or something.

Second, Above maybe 55, when I let off the gas to shift or just to coast I get a good vibration in the transition. And then, if I do take it up above 65ish I get a good vibration throughout the truck.

So, in hopes of trying to fix that I've:

Had a new driveshaft built
Got new tires
All new u joints
Rebuilt the np205
Got a rebuilt transmission
New clutch
New flywheel

But it really hasn't fixed anything. The transition vibration I mentioned is still really annoying.

And couple that with the issues I've been having with the clutch disengaging, and the amount of work I've been putting into the truck. Makes me wish...no, I'm not even going to say it.

Anyway, had to vent.

[ahale2772]

do a cylinder drop test, at idle, or set the idle up a bit.

crack one injector nut at a time and listen for the rpm drop from that lost cylinder. (wear gloves/eye protection)

If one cylinder makes more off a difference then the others (or one cylinder makes not much difference) then you know you have an injector/DV problem that you need to check. each cylinder should show a consistant rpm drop

i feel like your vibration might be caused by the engine, if you have a serious miss or stuck injector it could transfer the vibration throught the drivetrain

my truck HAD a vibration with rpm once, it was the balancer. the rubber was falling out and caused it too vibrate at only like 2100rpm

[Subliminal]

I guess I should have mentioned that I replaced all 6 injectors a while back and it made no difference whatsoever, so I kind of ruled out injectors. Forgot about that until you mentioned it.

[JustinRhodes]

I still think maybe you should try cracking the injector lines. it could rule out the dvs. Maybe a piece of rubber from the plunger got lodged in one of the dvs? Just thinking outloud here

[Subliminal]

I've definitely done that before, but I can try again. Basically, I don't really notice much difference when cracking any of the injectors, other than it sprays fuel everywhere...still seems to run about the same.

[ahale2772]

sounds like you have done lots to try and fix the issue.

kingpins? they really dont show issues till under load... might be worth pulling the top spring retainer caps off to take a gander at the nylon cones

[Subliminal]

Ha. I guess I left some stuff out. New upper and lower kingpins, and I did tie rod ends, drag link and front u joints at the same time.

[ahale2772]

anything else you car to tell us???

motormounts?
fan clutch tight?

[Subliminal]

All mounts are new, haven't messed with the fan on the front. Was thinking about yanking it off, now that it's cold out, and giving it a shot.

[JustinRhodes]

Your gonna have a new truck by the time you get it figured out

[diesel freak01]

This may sound stupid but, my truck had a vibration at speed above 45 or so caused by the brake rotors and the wheel stud holes being out of round. When was the last time you had your tires balanced? I know this sounds like stupid simple stuff but it may help.

[Subliminal]

Funny, I bought the truck for $5500 and have put about that much into it chasing gremlins.

The tires haven't been balanced for a while, and they could be responsible for some vibration, but i think the thing that leads me away from the tires is that the worst of the vibrations are when going from cruise to coast...or when you're on the highway and you hold the pedal just right so you're really not giving it any power, but it's in that weird spot between power and coast.

[1STGENFARMBOY]

You should be able to rule out the flywheel in (N) and just slowley take up the rpm's and see if you can feel it.

could also be a harmonic balencer.

[BILTIT]

^^^I would look at the balancer.

[cougar]

I feel your pain. I went through the same with my 91 and finally got it all sorted out.
Things not mentioned are;
Rear brake adjustment. I was amazed to find out how much that cured.
Ditch the OEM front rotors and get the best you can get. That ended my almost biweekly rotor turning due to warp-age.
As far as the vibration during shifting;
Check your flywheel bolts.
R&R your pilot bearing if you didn't during your clutch change.
and check the tube over the input shaft that the through out bearing rides on. I had one of those broke by the Dodge dealer once.

Oh, steering gear plate and front leaf spring mounts.